Common Sleep Disorders


  1. Insomnia: wants to sleep but cannot
  2. Sleep Deprivation: does not want to sleep but can; problem of sleep quantity
  3. Sleep Apnea (obstructive): sleepy or tired during day, snores at night; problem of sleep quality
  4. Restless Legs Syndrome: leg discomfort relieved by movement, worse at night
  5. Parasomnias: abnormal actions during sleep that are disruptive to patient or family
  6. Circadian Rhythm Disorders: lack of harmony and synchrony with surrounding social or environmental sleep patterns 

Insomnia: (see Links)

Insomnia describes the most common sleep disorder in which the person wants to sleep, allows the necessary time in a comfortable environment, but cannot sleep the wanted amount.  It involves the inability to initiate sleep (onset), stay asleep (maintenance), or waking up too early, along with some degree of frustration at night and impairment during the day.   

Insomnia can be classified as acute or lasting less than one month and associated with some temporary stressful event, illness, perception, or thought.  Sleeping pills for a short duration work well in these situations, and the patient usually recovers the normal sleep routine.

Chronic insomnia is different, lasting over one month and usually for years.  The problem is more ingrained and difficult to manage.  Over 60% involve psychological issues such as anxiety, depression, stress, alcohol or drug use, etc.  Many also involve medical illnesses such as pain syndromes at night (e.g. arthritis), gastroesophageal reflux (heartburn), lung (e.g. asthma) or heart problems.  Other sleep disorders (see below) may be involved such as sleep apnea, restless legs, or shift work disorder (a circadian rhythm disorder).

However, chronic insomnia 100% of the time involves acquiring bad sleep habits (See Good Sleep Habits) that perpetuate and aggravate the problem.  Sleeping pills usually work for a short time or their effect wears off, which frustrates the patient even more.  Sometimes the expectations are unrealistic such as the patient who wants to sleep 12 hours per night.  Therapy by a trained expert who has an interest and experience managing sleep problems is usually the best initial approach.  (See Links: Websites and Books)

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Sleep Deprivation: 

This is the second most prevalent sleep disorder: the persons who can sleep but do not want to because they want to stay up and work, study, party etc.  This disorder is rampant among our younger people: high school, college, and late twenties and early thirties.  Many of these young people believe sleep is downright boring and will deprive them of the necessary time to work hard and party hard.  For these hardy, trendy, up and coming folks believe that sleeping 7 to 8 hours is for weak slobs or the older, sedate crowd.

Unfortunately these self-proclaimed smart people do not understand the basics of the science of sleep (see, and Dr. Dement’s book: The Promise of Sleep) and are actually dangerously ignorant.  A very important concept is sleep debt, which is accumulated if one does not sleep the adequate amount of time.  The higher the sleep debt, the greater the probability that the person will experience: fatigue, mood disorders, social problems, and performance problems at work or at school.

Sleep deprivation helps to explain such spectacular and tragic disasters as: the Exxon Valdez oil spill in Alaska, the Challenger Space Shuttle explosion, the Chernobyl Nuclear Plant meltdown in the Soviet Union, and the recent commuter plane crash in Kentucky.  In each of these situations there were highly competent professionals who had performed their jobs well for years and then went through a period where unusually high work demands deprived them of much sleep.   They then committed very simple, dumb mistakes that were not caught in time, nor even suspected, and resulted in tremendous public health disasters.

Approximately 33% of fatal truck accidents result from sleep deprivation.  In fact when truck accidents were initially studied by the federal government, the assumption was that many were due to alcohol and thus the prediction was that accidents would cluster at around midnight, when the bars would close.  However the accidents actually clustered long after that around 4 am, when the sleep deprived drivers finally dozed off behind the wheel. In addition 10% of fatal car accidents are due to sleep deprivation.  It has been shown that the impairment is the same whether one is drunk, sleep deprived (sleeping <4-6hours), or have sleep apnea.  In many states now, statues severely punish drivers who are sleep deprived and are involved in accidents.  The trend to pass such laws is growing.

Sleep deprivation also leads to obesity and less control of diabetes.  Persons who sleep less simply eat more, generally salty, fatty, and sweet snacks.  Lower body weight correlates with good sleep habits particularly in those who are middle aged.  Sleep is intimately related to eating and exercise.  At present this topic is undergoing very intensive research particularly in the area of hormones (e.g. leptin) that help control both hunger and sleep.

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Sleep Apnea:

sleep apnea

Sleep apnea refers to the lungs not receiving air during sleep.  It results from obstruction in the throat that blocks the air (obstructive sleep apnea); or the brain failing to give the command to breathe: central sleep apnea.  By far the most common condition, particular in the young and middle aged, is obstructive sleep apnea (OSA).  Although obesity is the greatest risk factor for OSA, especially in middle aged males, women, children, and the elderly need not be obese.

The most common symptoms of OSA are: night time snoring, that results from throat obstruction; and day time sleepiness, that results from non-refreshing, poor quality sleep at night.  However the patient is often not aware that the quality of their sleep is quite poor since they are sleepy and do spend usually 7 to 8 or more hours sleeping.  Yet, in addition they often take naps during the day and thus they don’t think they have a “sleep problem”, which usually means insomnia to them.  Also sleep apnea usually comes on gradually and the patient adapts to it and does not notice the harmful changes or rationalizes them.  Usually the bed partner notices the changes more readily and is a more reliable source of information.

In addition to snoring the patient with OSA during sleep can gasp for air, hold their breath for long periods, and suddenly snort (as the throat opens).  Sometimes they wake up, although usually they don’t know why.  OSA occurs more when the patient is in deep sleep, especially dreaming, and when the patient is on his back or supine.  Hypoxemia or low oxygen is a very important consequence of OSA that can be very harmful to the heart and brain.  Fearful of OSA, the brain often will not allow the patient go into deep sleep, and this compounds the lack of refreshing sleep that results in daytime fatigue and sleepiness.

Other consequences of OSA include: not allowing the bed partner to sleep and poor performance at work, school, or with sex (impotence). The patient can feel depressed and tired all the time.  A particularly important consequence of OSA is an increase in accidents, especially motor vehicle accidents. OSA is a risk factor for heart disease and strokes, just like high cholesterol.  Finally OSA worsens obesity, diabetes, and hypertension.

Sleep apnea needs a sleep study for diagnosis and control is usually achieved.

In summary sleep apnea is a very common, dangerous illness that was long ignored, but is easily diagnosed and easily treated.

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Another important, but less common, sleep disorder that can lead to sleepiness during the day is narcolepsy that usually begins during the teenage years or in the early twenties. Tragically it is often not diagnosed nor properly treated for many years or even decades, causing the patient enormous suffering.

Besides relentless daytime sleepiness, the other hallmark symptom of narcolepsy is sudden muscle weakness (cataplexy) that can affect the eyes, neck, throat, legs, arms but without loss of consciousness, lasting minutes.  This represents the intrusion of dreaming (and the attendant muscle paralysis) into wakefulness.  In fact narcolepsy represents a mixing of sleep and wake states. 

Sudden dreaming during the day can lead the patient to describe what appear to be hallucinations, and erroneously lead to the diagnosis of a serious psychiatric illness.  Unfortunately the wrong medications can then be given and the symptoms of narcolepsy will not improve or even worsen.  Another frightening symptom of narcolepsy is morning paralysis, in which the patient wakes up but cannot move for several minutes. Again this represents the paralysis of dreaming lingering on too long.  (See

Fortunately modern medications can adequately manage this devastating illness.  The problem remains its adequate and timely diagnosis.  Sleep studies are necessary to diagnose narcolepsy.

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Restless Legs Syndrome:

Restless Legs Syndrome (RLS) is an irresistible urge to move the legs, and this movement temporarily relieves a leg discomfort that is worse at night and during periods of inactivity.  It is also a very common disorder, like sleep apnea, that is easily diagnosed and treated, but also easily missed.

Although RLS is a disease of awake patients, this illness can cause insomnia, at times severely.  RLS can also be disruptive in social situations when the patient must sit for extended periods of time, such as at a dinner, public function, or long travel in a plane, bus, or car.  RLS is usually mild, and may not have to be treated with drugs, but it can be very severe and require expert care and multiple medications.

Restless Legs Syndrome can be familial and usually arises before age 30 and often in childhood, where it can be confused with ADHD (Attention Deficit Hyperactivity Disorder).  RLS can also be associated with other disorders: iron deficiency, pregnancy, renal failure, and peripheral neuropathy.  Treating or resolving the associated disorder can greatly improve or cure the RLS. 

Unfortunately many medicines can worsen RLS, including antidepressants, antihistamines, anti-nausea drugs, and major tranquilizers. Alcohol and caffeine are also offenders.

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These represent an interesting group of abnormal actions or behaviors during sleep that are disruptive to the patient or to the family and bed partner or even to the neighbors. They first of all must be distinguished from seizures or convulsions, or recognized as a secondary phenomenon to another sleep disorder such as sleep apnea.  In these cases it is important to treat the seizure or the sleep apnea directly.

Parasomnias are very common in childhood and include: sleep walking, talking, night terrors, nightmares, grinding teeth, head rolling/banging, and urinating in bed.

In adults an important parasomnia is REM Behavior Disorder, during which patients act out their violent dreams and at times injure themselves or their bed partners. As mentioned above while dreaming we are normally paralyzed for this very reason: so we will not act out our dreams. Luckily these patients respond well to medications.

Well trained sleep experts need to diagnose and manage parasomnias since often no treatment is necessary (especially in children that grow out of them) but at other times treatment is mandatory for dangerous and disruptive conditions. At times patients can engage in offensive acts that can lead to problems with the police and the courts. Diagnosis and treatment can be difficult under these circumstances.

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Circadian Rhythm Disorders:

This interesting group of disorders involves the body’s internal clock not being in harmony or synchrony with the external light/dark cycle or the social cycle.
There are two basic types: internally or externally driven.  The internal types include a rather common disorder in teenagers: Delayed Sleep Phase Disorder (DSPD).  In this illness the internal clock of these teenagers shifts several hours into the night such that instead of sleeping at 10pm they now need to begin sleep at 1 or 2am.  Thus they tend to wake up late and during school days they become sleep deprived with the attendant complications including doing poorly in their early classes.

A condition similar in the elderly (but in the opposite time period) is Advanced Sleep Phase Disorder (ADSD): in which the person needs to go to sleep earlier in the evening usually around 8pm, but then wakes up at 4am.  When this disorder occurs in a young, working population, often jobs are obtained that nicely fit this schedule.

The main externally driven disorder is Shift Work Syndrome that involves over 10% of night time workers.  Unfortunately the patient then is sleepy and tired during work hours and the performance is affected, while the same patient suffers from insomnia when they do want to sleep.  It is the worst of both worlds.  Even though it is such a common disorder it has only been studied extensively in the last 20 years.  There are various management techniques and medications available to control this disorder.

Jet lag is another common externally driven disorder that is common in this age of business globalization and world travel.  Often just patience is enough if only a few time zones are traversed, in particular if one travels east.  At other times medications are necessary.

An interesting aspect of the treatment of circadian rhythm disorders is the use of light therapy, since light so deeply influences our internal clock.

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